Kitchen ventilator damper actuator and control

Abstract

This invention relates to a kitchen ventilating system, where a kitchen hood communicates through an exhaust duct to the exterior atmosphere, where a fan in the duct operates for powered venting of the kitchen, and where a damper can be closed to separate the kitchen from the exhaust duct. This invention teaches means for shifting the damper between the closed position and the open position, which means is a fluid power actuator in the form of a power cylinder. The power cylinder is operated by water, typically from the same source as the regular kitchen water, and control valve means utilized between this source of water under pressure and the cylinder controls the shifting of the damper. The preferred system provides that the valve means shifts by spring pressure to the position corresponding to where the damper is closed and is electrically shifted to open the damper, so that should a power failure occur the damper will automatically be closed. Also, there is a pressure tank that retains sufficient water pressure to close the damper, even though the source of water may actually have inadequate or total loss of pressure.

I claim: 
     
       1. In a kitchen venting system having an exhaust duct and power fan means therein, and structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator, means securing the first and second members of the power actuator between said structure and damper to provide that extension and retraction of the power acutuator respectively shifts the damper between and to said positions, a source of fluid under pressure, a control valve between said source and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, said control valve being four-way having two operative positions that respectively interconnect two pairs of ports each consisting of an infeed port and an outfeed port, and one pair of infeed and outfeed ports being connected to opposite operative sides of the power actuator and the opposite pair of infeed and outfeed ports being connected to the source of fluid and to a drain, operable to have powered operation for both the extension and retraction of the power actuator and the resulting shifting of the damper. 
     
     
       2. A kitchen venting system combination according to claim 1, further including a pressure reservoir, a tee connecting the pressure reservoir to both the source of fluid and to the control valve, said pressure reservoir having sufficient storage capacity of fluid and pressure to operate the power actuator to shift the damper to the closed position even in the event of loss of pressure of the source upstream of the tee, and flow check means precluding discharge from the pressure reservoir other than toward the power actuator. 
     
     
       3. A kitchen venting system combination according to claim 2, further including means for biasing said control valve normally to the operative position that tends to shift the damper to the closed position, and electrical means to shift the control valve to the other operative position, whereby any loss of electrical power automatically causes the damper to be shifted to the closed position. 
     
     
       4. In a kitchen venting system having an exhaust duct and power fan means therein, and structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator, means securing the first and second members of the power actuator between said structure and damper to provide that extension and retraction of the power actuator respectively shifts the damper between and to said positions, a source of fluid under pressure, a control valve between said source and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, spray means to discharge water into the exhaust duct, control means to start a water discharge cycle, a timer responsive to the start of the water discharge cycle operable to delay for a few seconds the actual discharge of water from the spray means, and the control means further including means to shift the control valve without delay responsive to the start of the water discharge cycle effective to have the damper closed prior to the water discharge. 
     
     
       5. In a kitchen venting system having an exhaust duct and power fan means therein, and structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator, means securing the first and second members of the power actuator between said structure and damper to provide that extension and retraction of the power actuator respectively shifts the damper between and to said positions, a source of fluid under pressure, a control valve between said source and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, spray means to discharge water into the exhaust duct, said fluid for the power actuator being water, and said source of water for the power actuator being the same as is for the water discharge from the spray means. 
     
     
       6. A kitchen venting system combination according to claim 5 further including a control to start a water discharge cycle from the spray means, means in the control operable to delay for a few seconds actual discharge of water from the spray means even after the start of the water discharge cycle, and the control further including means to shift the control valve without delay responsive to the start of the water discharge cycle effective to close the damper prior to the water discharge from the spray means. 
     
     
       7. In a kitchen venting system having an exhaust duct and power fan means therein, and structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator, means securing the first and second members of the power actuator between said structure and damper to provide that extension and retraction of the power actuator respectively shifts the damper between and to said positions, a source of fluid under pressure, a control valve between said source and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, a pressure reservoir, a tee connecting the pressure reservoir to both the source of fluid and to the control valve, said pressure reservoir having sufficient storage capacity of fluid and pressure to operate the power actuator to shift the damper to the closed position even in the event of loss of pressure of the source upstream of the tee, and flow check means precluding discharge from the pressure reservoir other than toward the power actuator. 
     
     
       8. In a kitchen venting system having an exhaust duct and power fan means therein, and structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator, means securing the first and second members of the power actuator between said structure and damper to provide that extension and retraction of the power actuator respectively shifts the damper between and to said positions, a source of fluid under pressure, a control valve between said source and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, said control valve being four-way having two operative positions that respectively interconnect two pairs of ports each consisting of an infeed port and an outfeed port, one pair of infeed and outfeed ports being connected to opposite operative sides of the power actuator and the opposite pair of infeed and outfeed ports being connected to the source of fluid and to a drain, operable to have powered operation for both the extension and retraction of the power actuator and the resulting shifting of the damper, means for biasing said control valve normally to the operative position that tends to shift the damper to the closed position, and electrical means to shift the control valve to the other operative position, whereby any loss of electrical power automatically causes the damper to be shifted to the closed position. 
     
     
       9. In a kitchen venting system having an exhaust duct and power fan means therein, and structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator between said structure and damper to provide that extension and retraction of the power actuator respectively shifts the damper between and to said positions, a source of fluid under pressure, a control valve between said source and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, a pressure reservoir, a tee connecting the pressure reservoir to both the source of fluid and to the control valve, said pressure reservoir having sufficient storage capacity of fluid and pressure to operate the power actuator to shift the damper to the closed position even in the event of loss of pressure of the source upstream of the tee, flow check means precluding discharge from the pressure reservoir other than toward the power actuator, means for biasing said control valve normally to the operative position that tends to shift the damper to the closed position, and electrical means to shift the control valve to the other operative position, whereby any loss of electrical power automatically causes the damper to be shifted to the closed position. 
     
     
       10. In a kitchen venting system having an exhaust duct and power fan means therein, structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, and electrical power on-off control means for operating the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator, means securing the first and second members of the power actuator between said structure and damper to provide that extension and retraction of the power actuator respectively shifts the damper between and to said positions, a source of fluid under pressure, a control valve between said source and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, means for biasing said control valve normally to the operative position that tends to shift the damper to the closed position, and electrical means including the on-off control means operable to shift the control valve to the other operative position, whereby manual actuation of the on-off control means to power the fan means also automatically causes the damper to be shifted to the opened position, and whereby manual actuation of the on-off control means to stop the fan means and including otherwise the loss of electrical power at the on-off control means automatically causes the damper to be shifted to the closed position. 
     
     
       11. A kitchen venting system combinaton according to claim 10, further including spray means to discharge water into the exhaust duct, a source of water under pressure, a control valve between the source of water and the spray means, and means to open the control valve to spray water automatically responsive to the manual actuation of the on-off control means to stop the fan means. 
     
     
       12. A kitchen venting system combination according to claim 11, further providing that the fluid used to power the power actuator is water and the source thereof is the same source as for the water spray means. 
     
     
       13. In a kitchen venting system having an exhaust duct and power fan means therein, and structure defining a passage between the kitchen and the exhaust duct whereby kitchen fumes are vented through the passage upon operation of the fan means, the improvement comprising the combination of a damper, means supporting the damper to shift between a closed position blocking the passage and an opened position allowing flow through the passage, a fluid power actuator having first and second members that move relative to one another upon the extension and retraction of the power actuator, means securing the first and second members of the power actuator between said structure and damper to provide that extension and retraction of the power actuator respectively shifts the damper between and to said positions, a source of water under pressure, a control valve between said source of water and the power actuator operable to pressurize and exhaust the latter to control the extension and retraction thereof, spray means to discharge water into the exhaust duct, a control valve between said source of water and the spray means, and an on-off control for the venting system including means to sense inadequate pressure of the source of water and responsive thereto to preclude operation of the fan means and actuation of the damper control valve to shift the damper to the opened position even upon manual actuation of the on-off control to otherwise power the venting system. 
     
     
       14. A kitchen venting system combination according to claim 13, further including wash control means for operating the power actuator control valve to have the damper shifted to the closed position and for operating the spray means control valve effective to discharge water from the spray means each responsive automatically to manual actuation of the on-off control for stopping the venting system.